Six states will hold their votes next week, including the battleground state of Michigan, which Sanders narrowly won four years ago.

California is still leading towards Sanders and these Super Tuesday matchup, but Biden, who is the presumptive winner in Main, leads the delegate count.

CBS News political correspondent Ed O'Keefe is in Washington with what the candidates are doing to keep up the fight.

This idea that we didn't have a movement look at the results.

Look at who's showing up.

Former Vice president Joe Biden is calling his campaign a movement, while Senator Bernie Sanders acknowledges that his movement has struggled to bring out new voters.

Think that will change in the general election, But I am on to be honest with you.

We have not done as well in bringing young people will put process.

It is not easy.

Ahead of next week's critical primary in Michigan, a state president, Trump won by just over 10,000 votes.

Sanders is highlighting his differences with Biden, Michigan was decimated by a terrible, terrible trade deals NAFTA PNTR with China, which cost our country some four million good paying jobs.

I walked the picket lines against NAFTA, went to Mexico to see what NAFTA would do.

Joe voted for those terrible grins.

Biden did vote for NAFTA, but the former vice president says he believes future trade negotiations should include input from labor and environmental leaders.

After his surprising turnaround on Super Tuesday, Biden's campaign is getting another boost.

I'm glad to say I endorse Joe Biden.

Former New York City Mayor Michael Bloomberg spent more than $500 million on his own.

Run said he'll support Biden's candidacy.

It's the Bloomberg comes onboard Barden of the candidates, and he will solidify his support with the political leader.

We're taking that on.

We're running a grassroots campaign.

But the Sanders campaign appears to be seeking to broaden support.

This new ad featuring former President Obama is evidence of that Bernie is somebody who has the virtue of saying exactly what he believes.

Let us bring in CBS News campaign reporter care according to talk more about this.

Okay, as we look forward to the next round of contests and gets the next Super Tuesday.

What does Sanders need to do to maintain and, some might argue, regain momentum?

Yeah, I think you're absolutely right.

Emory needs to regain momentum.

He needs to win.

When we look at what happened on Super Tuesday, there were some unexpected losses for the Sanders campaign, particularly when you look at Main and Minnesota, those air to states that he won in 2016 and what we have known Bernie Sanders.

Biggest obstacle this election has been.

If he can expand his base if he can get more votes than he did last time.

And losing states that you won four years ago is not a good way to gain momentum.

Something I think we're all looking at and waiting for is what is going to happen with Senator Elizabeth Warren.

We learned yesterday that Senator Sanders and Senator Warren had spoken over the phone.

A senior staff told me that was a private conversation, just the two of them, uh, speaking for a short time about what her future holds.

And Sanders told us yesterday that he wasn't sure what she was going to do, that she needed time to make a decision.

He wanted to respect that and give her space.

But it's going to be really interesting to know, uh, to find out what is going to happen there.

Obviously, Senator Warren is is Senator Sanders fellow progressive in the race, and we saw moderates consolidate before Super Tuesday and we saw how much that helped Vice President Biden.

So we're waiting to hear if Senator Warren is going to drop out.

When will she do that?

And if she does Well, she endorsed Senator Sanders.

There's no guarantee that she will s.

So that could be a way that he could pick up a little more mo mentum heading into the next round of elections.

Kara, what is the prospect?

It's interesting.

You pointed out that hey has not been doing as well in states that he won back in 2016.

So as we look ahead to next week's primaries, housing positioned in those primaries I mean, is he is he pulling better than he did in 2016 or not as good?

Well, we just saw Ed mentioned this in his piece, but I think it's a really good idea to isolate Michigan when it comes to seeing how Bernie Sanders is doing.

After taking a few hits on Super Tuesday Michigan, he won by a point and 1/2 over Secretary Clinton, 2016.

It was a bit of a bit of an upset for Sanders, and it's going to be interesting to see if he can again put a state in the win column.

He needs to start expanding his base.

And when it comes to Michigan, what we can expect from Sanders hit on a lot is trade.

We hear him now when he's criticizing the vice president.

He talks about the way that Biden funds his campaign, and he talks about Biden's senatorial voting record.

And one of those things is on trade.

Biden supported NAFTA.

Bernie Sanders vigorously opposed NAFTA, and Bernie Sanders is gonna go into Michigan.

Actually, as he did in 2016 regarding Secretary Clinton, he's gonna go into Michigan and tell Michiganders NAFTA destroyed the job market in Michigan.

It took millions of jobs out of this country, Uh, and people, especially in the Rust Belt like Michigan, suffered because of it.

So so look for him to hit on that he needs to try to coalesce those working class voters that are also very popular amongst Joe Biden to try and gain some more mo mentum.

So Bernie Sanders was actually on Rachel Maddow last night, where they talked about the new rules in place When it comes to super delegates at the Democratic convention, something that he participated in, he helped us to hammer out those new rules.

Let's take a listen to what he had to say on the first ballot.

There will be no superdelegates.

So in other words, we go into the first ballot.

It is representatives, delegates who are represented by the people.

And I think that that's right.

And what I have said is that I think it would be a really, really disaster for the Democratic Party.

If you know I'm running against you and you have more votes than me and I say, Well, wait a second.

I don't want Rachel.

I want somebody else who didn't get as many votes as she did.

Let's have the super delegates vote on the second ballot.

You know what that would do?

The democratic electorate.

People say the person I got the most votes didn't get selected delegates most elegant right.

So even with these new rules, there are several ways that superdelegates could affect the outcome of the nomination.

Can you just explain it a little to us?

Yeah, this is complicated.

We're all a little bit confused about it.

Sometimes it has changed since 2016.

As Senator Sanders said, he, his team was actually responsible for changing the rules.

There are multiple rounds of voting multiple ballots when it comes to the DNC in July and on the first ballot are regular delegates.

Now a delegate you guys will remember from the Iowa caucus, for example, a precinct captain could be a delegates.

More ordinary people.

Uh, but when you look at a super delegate, ah, super delegate is a DNC official or an elected official politician.

And if you speak Bernie Sanders like I've I've become fluent in and elected official or a DNC member is a member of the political establishment, right?

And and we know that the Sanders campaign is all about fighting the political establishment, and they're worried about the power those superdelegates have now what what he's saying about plurality and second ballot.

What Bernie Sanders is trying to prevent eyes a situation where he and vice president Biden essentially run neck and neck throughout the rest of the year.

And if he doesn't reach the magic number of 1991 doubt delegates, which is a majority, then we start talking about pluralities and second ballots.

What I think is really interesting.

Glad Anne Marie is for as long as I've been on this beat almost a year now.

Whenever you talk to Bernie Sanderssupporters, they are.

If they're worried about anything, it's not about his health.

It's not about his record.

They're worried about the DNC tearing this race away from Sanders.

They're worried about it.

Being rigged is a word that we hear a lot.

They feel like that happened to Senator Sanders in 2016.

When you look back at superdelegates who voted on the first ballot.

Hillary Clinton had almost 500 superdelegates to her name before Bernie Sanders even got in the race and what he will say, he used the metaphor often.

When he talks about that, he'll say it's like starting 100 yard dash with someone else getting a 30 yard head start, so it's going to be interesting to see how Sanders supporters coalesce behind him as we hear Maur of this approaching delegate conversation because they're really worried about this happening to him again.

And if they are, keep an eye on those fundraising numbers because they want to support him.

They want to make sure that this race isn't taken away from him.

Really interesting.

Carol Cordy.

Always great to have you.

Thank you so much for your reporting from the campaign trail.

Appreciate it.

Well, CBS n has you covered for the March 10 primaries will bring you a live preview coverage starting next Tuesday, 7 a.m. Eastern, then at 5 p.m. Eastern will have a special edition of Red and Blue to get you set for the big day in the presidential race.